Chaf. XXXI.

PRINCIPLES OF PROPORTION.

1607

house exhibits the most perfect proportions as well as appropriate decorations; the eightwindows, divided into four days, have their heads filled in with circles set out uponequilateral triangles; the vaulted stone roof rests partly upon the octangular central pillars,3 feet in diameter, surrounded by sixteen small columns, one at each angle and anotherbetween ; the height of the pillar is 22 feet 8 inches.

Thoroughly to comprehend the expression, as well as use of the various members foundin the architecture of the middle ages, we must trace the progress made in vaulting, andobserve the changes it underwent, from the simple cylindrical to the more complex anddifficult display of fan tracery or conoidal arches. The ridge ribs, or Hemes , as they aretermed, in the crypt of the Chapter-house at Wells, pass from the centre of the building tothe middle of each buttress ; the diagonals, or croissees , mitre into them as well as into theformerets or ribs against the outer walls.

In the vaulting of the Chapter-room, we have evidence of greater refinement, and an

CHAPTER-HOUSE AT WELLS : SECTION,

Fig. 3009.

improvement in the decoration, by the addition of a number of intermediate ribsterminating against the octangular one in the middle.

At a later period we find transverse ribs made use of, then others between; butalthough the design may seem complicated, yet when laid down the plan will as-sume the greatest simplicity, as shown in the division representing the groining of thecrypt.

When this system had been carried out to a considerable extent, the fan tracery wasintroduced, and although apparently more difficult of execution, it is far more scientific inits application and arrangement, evincing a higher knowledge of mathematical principlesand geometry, and is another evidence of the gradual progress of the mind towardsperfection in this style of architecture.

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